ACCORDING TO THE PASSAGE, IT IS BELIEVED THAT THE LARGEST EXTINCTI...
54. According to the passage, it is believed that the largest extinction of a species occurred
A. 26 million years ago
B. 65 million years ago
C. 225 million years ago
D. 250 million years ago
Read the passage and choose the best answer for each question (55-64) below.
By far the most important United States export product in the eighteenth and nineteenth
centuries was cotton,
favored
by the European textile industry over flax or wool because it was
easy to process and soft to tile touch. Mechanization of spinning and weaving allowed significant
centralization and expansion in the textile industry during this period, and at the same time the
demand for cotton increased dramatically. American producers were able to meet this demand
largely because of tile invention of the cotton gin by Eli Whitney in 1793. Cotton could be grown
throughout the South, but separating the fiber – or lint – from the seed was a laborious process.
Sea island cotton was relatively easy to process by hand, because its fibers were long and seeds
were concentrated at the base of the flower, but it demanded a long growing season, available
only along the nation's eastern seacoast. Short-staple cotton required a much shorter growing
season, but the shortness of the fibers and their mixture with seeds meant that a worker could
hand-process only about one pound per day. Whitney's gin was a hand-powered machine with
revolving drums and metal teeth to pull cotton fibers away from seeds. Using the gin, a worker
could produce up to 50 pounds of lint a day. The later development of larger gins, powered by
horses, water, or steam, multiplied productivity further.
The interaction of improved processing and high demand led to the rapid spread of the
cultivation of cotton and to a
surge
in production. It became the main American export, dwarfing
all others. In 1802, cotton composed 14 percent of total American exports by value. Cotton had a
36 percent share by 1810 and over a 50 percent share
in 1830. In 1860, 61 percent of the value of American exports was represented by cotton. In
contrast, wheat and wheat flour composed only 6 percent of the value of American exports in that
year. Clearly, cotton was king in the trade of the young republic. The growing market for cotton
and other American agricultural products led to an
unprecedented
expansion of agricultural
settlement, mostly in the eastern half of the United States---west of the Appalachian Mountains
and east of the Mississippi River.